Process for making homologues of styrol from aromatic hydrocarbons



Patented Sept. 8, 1925.

' 450 C. to approximately 700 U ITED STATES 1 I 1 1,552,874 PATENT OFFICE...

IWAN' QSTROMIBLENSKY AND MORRIS G. SHEPARD, OF NEW YORK, N. Y.,.A.SSIGNOR-S TO THE NAUGATUGK'CHEMIGAL COMPANY, O]? NAUGATUCK, CONNECTICUT, A COR- IOBLTION OI CONNECTICUT.

PROCESS FOR MAKING HOMOIDGUES OF STYROL FROM AROMATIC HYDROCARBONS.

I Drawing. Origins application filed Kay 7, 1924, Serial No. 711,583. Divided and this application I fled January 80, 1925. Serial No. 5,891;

To all whom it may concern:

Be it known that we, IWAN OSTROMISLEN- any and Monnrs G SHEPARD, a citizen of Russia and a citizen of the United States, respectivel both residents of New York, county an State'of New York, have 1nvented certain new and useful Improvements in Processes for Making Homologues of Styrol from Aromatic Hydrocarbons, of which the following is a full, clear, and exact description.

This invention relates to the production of styrol homologues from hydrocarbons having eight or more carbon atoms such as homologues and analogues of ethyl benzol, xylol and the like. I

This invention is a division of our coending application Serial No. 711,583, filed he object of the present invention is to provide a process for preparing the homologues of styrol, such as the alkylated, or more specifically methylated and/or ethylated styrols and'similar compounds.

Another object of the invention is to provide a simple, economical method of carrying out pyrogenic decomposition of the raw materials to produce these homologues of styrol.

The invention accordingly comprises a process for making homologues of styrol by heating a hydrocarbon having at least eight carbon atoms and at least ten hydrogen atoms at a temperature of apgroximately thus partially decomposing the hydrocarbon to form a compound having the general formula ArCHzCH where Ar represents aryl. More specifically the invention consists in producing a compound of the general formula AI'CI-LOH, where Ar represents aryl containing an alkyl group. I

This application is a continuation in part of Our application Serial No. 648,751, filed June 30, 1923.

For carrying out the invention, the apparatus described in our copending application Serial No. 711,583, filed May 7, 1924:, may be employed. I I

Briefly this apparatus consists of a source of carbon dioxi which the gas is led by a pipe through a flow-meter whence it is introduced into the interior of an iron pipe which is vheated to e or other neutral gas from the required temperature by gas burners or other sultable means. Communicating with the non tube through a suitable valve and sight glass is a container for the hydrocarbon whlch constitutes the raw material in the recess. The temperature is determlned tor example by means of a thermo couple, the temperature determination bemg made on the gas in the interior of the tube at about the middle. A. condenser and receiver are provided and a gas holder is connected therewith to collect uncondensable gases.

Generally speaking the processes for producing styrol, its homologues and analogues may be divided into two groupswhich are designated as follows: (1) dehydrogenation of ethyl benzene or its homologues at high temperature (450700 C.) and (2) splitting off hydrocarbons from various homologues or analogues of benzene which have more than two carbon atoms in a side chain (soc-700 o.

The general formulae for these reactions may be represented as (1) ArG I-I R:H +ArCH CH Where Ar represents aryl and R represents an element such as hydrogen.

(Q) ArC H MzMH-l-ArCH:OH where Ar 1's aryl and M represents an alkyl radical.

In the second general formula MH signifies the hydrocarbon which is split 01f.

If a compound of the general formula ArC H R, where R:hydrogen is employed the product is styrol provided the Ar is'not alkylated. When, however,,an alkyl group or groups are introduced into the Ar,- then homologues of styrol result. -The general formula is then R'ARC HJt, where R represents a substitution in the aryl, being H uey: sop p:

The following is a" tabulation of results obtained by the deh drogenation of the isomer xylol and homo ogues of ethyl benzol into those of styrol according to a process similar to that set forth in our copending application Serial No. 711,583, filed May 7, 1924, for dehydrogenation of ethyl benzol toform styrol therefrom. 'The following table .gives the conditions of operation of the apparatus described in application Serial No. 711,583, filed May 7, 1924, items C, D, E, and F giving the explicit conditions of operation.

. Bgilinfi tmperature of original mix- 140. 175-185 145-100 100-165 180.

Nature of active hydrocarbon. Xylol- 1.3 5 dime thy] O r t h o m e t h yl Paramethyl ethyl Dlethyl-benzol ethfl benzol. ethyl benzol: benzol. Amount in grams per minute 15 gms 0 62 gm y 18 gms. Duration of process 1 hr. 7 min 611. 45 m 45 mlns. Mixture subjected to pyrogenlzation in 1000 gins 250 gm 849 gms.

gms. Temperature of furnace C.) 650 640-650 580-6202; 640650 050. Liquid products obtained 944 gms 225 gms 97 gms 199 gms 800 gms. Dry hydrocarbons distilled with steam. 833 gms 178 gmS 85 gms 170 gms 684 grns.

Nature of product obtained Styrol Metamctadime- 0 r t h o m e t h y l Paramethyl sty- Ethyl styrol.

. thyl styrol. styrol. rol. Content of styrol homologues in distil- 5.7%.. 31.7%.- 28.0%.. 35.7% 23.8%.

late (steam) by analysis.

Whether the process is carried out inriron or quartz tubes the results are substantially as given above. Actually the above results were gotten using an iron tube for xylol and a quartz tube for the other substances. The quartz tube had the following dimensions: 1" diameter by 27" long. It has been found that the relationship of the volume in the heating chamber, the rate of flow and temperature exists in a similar way for products other than ethyl benzol which may be expressed mathematically by the formula given in connection with the process employing ethyl benzol.

Instead of using the homologues of ethyl benzol, etc. separately, it may sometimes be desirable to pass mixtures of ethyl benzol and/or of its homologues through the heated tube to obtain a solution whichv contains styrol and its homologues or the homologues alone depending upon which was used as the starting material. For this purpose mix tures of ethyl benzol and its homologues may be conveniently obtained by ethylating mixtures comprising benzol, toluol and xylol as for example the fractions obtained from coal tar, gas tar, etc and boiling from 80 G-tO 130 C.

As many apparently widely different embodiments of this invention may be made process for making compounds of I having the general formula R'ArC l-LR where R represents an element, to a temperature of approximately 450 (IL-700 C. and partially decomposing the C,H,R thereof to yield CH:CH

2. A process for making compounds of the type R ArCH: CH where Ar represents aryl, and R represents a substitution in Ar which comprises heating a hydrocarbon having the general formula RArCJ LR where R represents hydrogen, to a temperature of approximately 450. C. to approximately 700 C., and splitting hydrogen from the side chain thereof to yield compounds of the formula. ArCH: CH I 3. A process for making homologues of styrol which comprises heating alkylated alkyl benzols of the type having two or more carbon atoms in at least one of the alkyl substitutions and splitting hydrogen from the alkyl group containing at least two parbon atoms to form an alkylated styro 4. The process for making alkyl styrols from isomers of alkylated ethyl benzols which comprises splitting hydrogen from a side chain of said ethyl benzols which contains at least two carbon atoms.

5. The process for making methyl styrols from isomeric methyl ethyl benzols which comprises passing the vaporized methyl ethyl benzol through a conduit heated to a temperature of approximately 450 C. to approximately 7 00 0., splitting hydrogen from the ethyl radical thereof to form isomeric methyl styrols.v

Signed at Cromwell, Connecticut, this 26th day of January, 1925.

IWAN OSTROMISLENSKY.

Signed at New York, New York, this 28th day of January, 1925.

MORRISG. SHEPARD. 

